Have you tried #4's yet? They work much better for me, especially with a tighter choke. I don't think spending a bunch of money on a choke is going to help you. They are all pretty much the same except for the constriction. If you get a new choke with the same constriction as the one you have now don't be shocked if you get nearly the same results. There really isn't anything that high tec about chokes in my opinion.

The key is finding the right choke size and load that works in your gun.

I think 40 yards is pushing it with a 12 ga 3 inch load anyway.

Good luck, let us know what you find out.

Paul